It's all about mouth size. GSH because they reach a larger size have a larger mouth than the other listed forage species. Banded killies have a more upturned mouth designed for surface feeding and is smaller in general than the other shiner species. The other shiner species only reach about 4.5" or less max, so they never get big enough to really grow a mouth large enough to steal bait.

I have found that stocking the the other species first and giving them the time to multiply and fully adapt to the pond produces better results. I would stock the GSH at the same time as the original SMB stocking. This is assuming you are stocking GSH in the 3"-4" range and SMB of about the same size. This way the GSH do not get too big a jump start on your SMB. Otherwise you may get a very numerous original stocking class of GSH which can cause issues. These include GSH being very predecious on the eggs and fry of other forage fish species. So they may really reduce the reproductive potential of the other species which are less prolific and more desirable. Giving those other species a jump start without the presence of GSH gives them a better chance at establishing themselves and staying present in the pond even after SMB are present and reproducing. Stocking the GSH at the same time as the SMB means those GSH will always be too big for the SMB to feed on. They will be the future breeders of your pond. As they die of old age, you hope that your pond has the correct spawning and rearing areas that allows a few GSH born in your pond to reach adulthood and spawn themselves, thus keeping GSH present in your pond but not so numerous as to cause issues.